Removal of a mares ovaries

[BigHrider]

Unfortunately my friends mare lost a foal. The foal was unexpected and therefore the mare didnt have the proper scans and care.
The vet has advised my friend that the mare "is unsuitable for foaling" and has suggested removing her ovaries with standing keyhole surgery. This is something I havent heard of, please could you reply if you have had experience of this or have heard if this is ok

 

[KarynK]

It is a fairly common practice in the USA where they spay mares quite regularly when they are not destined for breeding. In some American breed registries, they will allow animals of unknown or unproven parentage onto the main registers only if they are gelded or spayed.

Here is a link to an article about spaying for you
http://www.horsekeeping.com/horse_management/spayed_mare.htm

 

[holiday]

We have a mare in the yard who is just recovering from this operation, although only one ovary was removed, she is making a very good recovery and due to have stitches out next week. It is still a newish op over here this particular mare had a ovarian tumour.

She is to have 6 weeks box rest before reassesment for turn out and coming back into work.

Although quite poorly the day after is back to her normal self and quite happy and came home only a few days after the operation.

 

[S_N]

Yep, we have a mare here at work who has had her ovaries removed. Sounds odd to have such a mare on a stud, but she gets lots of action, teaching new stallions their new job....

 

[KarynK]

Yes forgot about that they use ovariectomized mares in breeding as jump mares for teaching stallions and for collecting for AI.

 

[Tharg]

So the mare is still up for it even it no longer produces oestrogen?

 

[sallyf]

No she is given a drug called oestradial to make her believe that she is in season

 

[AndyPandy]

Not all mares need to be treated with oestrogens in order to be a jump mares, although it will certainly make the majority act as if they were "in season".

The reason a mare is -not- "up for it" is because she has progesterone circulating in her blood. The progesterone is produced by the corpus luteum; a structure on the ovary produced after ovulation.

If the mare's ovaries have been removed, then although she doesn't produce oestrogen any more, she doesn't produce progesterone either. This means that she won't reject the stallion's advances (unless she is psychologically conditioned to reject stallions which some are).

So, she is not "up for it" or "in season", but nor is she in dioestrus (the period between ovulations when progesterone is the dominant hormone); and it's this fact that allows them to be used as tease or jump mares.